This report presents an assessment of the effectiveness of a hydrotest in exposing defects in new and existing onshore and offshore pipelines. The study includes an assessment of the type and size of flaws that testing can and cannot identify through pressure testing for new lines and retesting for existing lines.
The study included an assessment of gas (air, nitrogen, methane, etc.) versus water pressure testing to assess leak tightness involved comparing the detectability of flaws based on gas pressure testing at either the maximum allowable operating pressure (MAOP)...
The study included an assessment of gas (air, nitrogen, methane, etc.) versus water pressure testing to assess leak tightness involved comparing the detectability of flaws based on gas pressure testing at either the maximum allowable operating pressure (MAOP) or up to 80 percent of specified minimum yield stress (SMYS) and water testing at pressures from 90 through 110 percent of SMYS.
The study includes some evaluation of alternatives to preservice hydrotesting as the impact of hydrotesting based on the toughness of the pipe steel.